To improve transmission performance of a link and throughput of a communications system, a multiple-input multiple-output (MIMO) technology becomes one of key technologies in the field of wireless communications. As the MIMO technology continuously develops in recent years, the MIMO technology will be more widely applied in various wireless communications systems.
In the MIMO technology, a transmitter in use usually includes multiple transmit channels and one feedback channel. The transmit channels in the transmitter are separated in a space shielding manner such as cavity separating or increasing a physical distance, so as to reduce interference among the transmit channels. However, a signal of the transmit channel may leak to the feedback channel, that is, the signal in the transmit channel may interfere with the feedback channel, and an interference signal on the feedback channel may interfere with the transmit channel, thereby leading to distortion of a transmit signal.